Theoretical and experimental research on a new high-temperature superconductor, yttrium hydride (YH6) was conducted by an international team led by Artem R. Oganov, a Professor at Skoltech and MISIS, and Dr. Ivan Troyan from the Institute of Crystallography of RAS. The research can be read in the journal Advanced Materials.
One of the three highest-temperature superconductors known to date also includes Yttrium hydrides. Material with an unknown S-C-H composition and superconductivity at 288 K is a leader among the three followed by LaH10, lanthanum hydride with superconductivity at temperatures up to 259 K. Then comes the researchable subject i.e., yttrium hydrides, YH6, and YH9, with maximum superconductivity temperatures of 224 K and 243 K, respectively.
High Temperature Achieved
In 2015, the superconductivity was predicted of YH6 by Chinese scientists. Maximum superconductivity temperatures of all these hydrides are achieved at very high pressures: 2.7 million atmospheres for S-C-H and about 1.4-1.7 million atmospheres for LaH10 and yttrium hydride, YH6. The major roadblock for quantity production is the high-pressure requirement.
Prediction of the highest-temperature superconductors was first to don in theory and then was experimentally created and investigated. Theoretical predictions are made by chemists while studying new materials and then testing new material in practice.
Oganov commented that –
“First, we look at the bigger picture and study a multitude of different materials on the computer. This makes things much faster. More detailed calculations follow the initial screening. Sorting through fifty or a hundred materials takes about a year, while an experiment with a single material of particular interest may last a year or two.”
Irregularity in Real and Theory Results
Prediction of critical superconductivity temperatures, in theory, has an error of 10-15% and similar results are observed in critical magnetic field predictions. However, the results observed in theory and experiment are quite different for YH6. The critical magnetic field observed in the experiment is 2 to 2.5 times greater as compared to theoretical predictions. Such a discrepancy is observed for the first time by the scientists which are yet to be explained. The possible reason for this irregularity is due to additional physical effects that were not accounted for in theoretical calculations.